We have irradiated some GaAs/AlGaAs heterostructures with 80 keV He+ ions and studied bombardment-induced changes of the electrical resistivity and the carrier density of a two-dimensional electron layer located at the intersection between a GaAs buffer and an AlGaAs spacer. The whole structure was so thin that the projectiles passed through the two-dimensional electron layer and stopped in the supporting substrate. The resistivity and the carrier density of the samples were determined at temperatures between 1.2 and 4.2. K before and after the bombardments, which were carried out at room temperature. The carrier density was determined from Shubnikov-De Haas oscillations. An interesting result is that the resistivity depends strongly on the projectile fluence, in contrast to the carrier density. As an example, a fluence of 3 × 109 He+ions/cm2 doubles the resistance but reduces the carr density by 5% only.
|Journal||Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms|
|Publication status||Published - 1990|
|Event||13th International Conference on Atomic Collisions in Solids - Århus, Denmark|
Duration: 7 Aug 1989 → 11 Aug 1989
Conference number: 13
|Conference||13th International Conference on Atomic Collisions in Solids|
|Period||07/08/1989 → 11/08/1989|